CHEMISTRY I: ATOMS AND MOLECULES
Most atoms contain all three of these types of subatomic particles—protons, electrons, and neutrons. Hydrogen (H) is an exception because it typically has one. Atoms | Electrons and energy | Chemical Bonding | Chemical reactions and Some scientists propose the neutron is made up of a proton and electron-like. The atomic model consists of a nucleus containing protons and neutrons, surrounded by electrons in shells. The numbers of particles in an atom can be.
All elements and the chemical reactions between them obey the same chemical and physical laws, regardless of whether they are a part of the living or nonliving world.The Nucleus: Crash Course Chemistry #1
The structure of the atom An atom is the smallest unit of matter that retains all of the chemical properties of an element. For example, a gold coin is simply a very large number of gold atoms molded into the shape of a coin, with small amounts of other, contaminating elements.
Gold atoms cannot be broken down into anything smaller while still retaining the properties of gold. A gold atom gets its properties from the tiny subatomic particles it's made up of.
Matter, elements, and atoms | Chemistry of life (article) | Khan Academy
An atom consists of two regions. The first is the tiny atomic nucleus, which is in the center of the atom and contains positively charged particles called protons and neutral, uncharged, particles called neutrons.
The attraction between the positively charged protons and negatively charged electrons holds the atom together. Most atoms contain all three of these types of subatomic particles—protons, electrons, and neutrons.
Have students charge two pieces of plastic and hold them near each other to see if electrons repel one other. Ask students to make a prediction: What do you think will happen if you charge two strips of plastic and bring them near each other? Procedure, part 3 2 pieces of charged plastic Charge two strips of plastic Slowly bring the two strips of plastic near each other. Expected results The strips will move away or repel each other.
Since both strips have extra electrons on them, they each have extra negative charge. Since the same charges repel one another, the strips move away from each other. What happened when you brought the two pieces of plastic near each other?
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The ends of the strips moved away from each other. Use what you know about electrons and charges to explain why this happens. Each strip has extra electrons so they are both negatively charged. Because like charges repel, the pieces of plastic repelled each other.
Explore Have students apply their understanding of protons and electrons to explain what happens when a charged balloon is brought near pieces of paper. Materials for each group Small pieces of paper, confetti-size Procedure Rub a balloon on your hair or clothes.
Bring the balloon slowly toward small pieces of paper. Expected results The pieces of paper will jump up and stick on the balloon. What did you observe when the charged balloon was held near the pieces of paper? The paper pieces moved up and stuck on the balloon. Use what you know about electrons, protons, and charges to explain why this happens. When you rub the balloon on your hair or clothes it picks up extra electrons, giving the balloon a negative charge.
When you bring the balloon near the paper, the electrons from the balloon repel the electrons in the paper. Since more protons are at the surface of the paper, it has a positive change.
The electrons are still on the paper, just not at the surface, so overall the paper is neutral. Basically, it contains a nucleus, holding some number call it N of positively charged protons, which is surrounded by a cloud N of negatively charged electrons. The force that holds the electrons and protons together is the electromagnetic force. The number N tells you what element you have: The same electromagnetic force that draws opposite charged electrons and protons together tries to push the protons which all have the same charge away from each other.
To avoid this separation, another particle comes into play in the nucleus: Much like a proton in mass but without electric charge, the neutron is essential for holding the nucleus together.
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How are elements broken down into protons, electrons and neutrons?
For most elements, there are several possibilities as to how many neutrons can fit into the nucleus, and each choice corresponds to a different isotope of that element. Suppose you want to pull an atom apart. The first thing you need to do is get rid of the electrons. There are lots of ways to do this. You can shine light on the atom, or expose it to another form of electromagnetic radiation having an even shorter wavelength.